The present invention relates to an operator or drive mechanism for a casement window. Still more specifically, the present invention relates to a single casement window operator which may be used for both dual arm and split arm drive mechanisms. Still more specifically, the present invention relates to a casement window operator which incorporates a spacer underneath the base to provide a water barrier between the operator and the window.
Casement window operators are known and typically include a hand crank that drives a worm gear and an arm or lever which pushes the window sash open. The worm gear is meshed with a gear segment which is part of a lever or linkage assembly that is connected to the sash. The worm gear includes shafts at each end with one of the shafts being splined. The splined shaft is received in the end of the crank or handle. The worm gear and gear segment are partially accommodated within a housing or escutcheon with the splined shaft of the worm gear extending outward through the housing to mateably engage the crank. When the crank is turned, the worm gear causes the gear segment and lever to rotate which causes the sash to pivot on its hinges between open and closed positions.
There are three general types of casement operators. One type is a single arm operator. The single arm operator has an arm which pivots about an axis that is fixed with respect to the window frame and worm gear. The remote end of the arm carries a bearing which slides in a track mounted to the underside of the sash. The single arm operator is made in a wide range of sizes in order to accommodate a range of sash widths. An advantage to the single arm is its ability to open a sash. One disadvantage with single arm operators is the torque required to move the sash towards its fully open position. Specifically, because of the sliding connection between the arm and the sash, the torque required to move the sash increases as the sash moves between its closed and open positions. Near the fully open position, the amount of torque required to twist the handle or crank may be unacceptably high.
A second conventional casement operator is the split arm operator. This operator is similar to the single arm operator in that it includes a drive arm that rotates about a fixed axis with respect to the worm gear. However, a split arm operator also includes a second arm that has a pivot joint in the middle of the second arm and the remote end of the second arm is secured through a pivotable mounting to a fixed point on the sash. The split arm operator is manufactured in a variety of sizes so there is a split arm operator suitable for most sizes of residential windows. A disadvantage of the split arm operator is its difficulty in opening a sash. On the other hand, an advantage of the split arm operator is its ability to extend the sash to its fully open position.
A third conventional type of window operator is the dual arm operator. The dual arm operator includes features common to both the single arm and split arm operators. Specifically, the dual arm operator includes one arm which rotates about a fixed axis in the housing and which carries at its far end a bearing to slide in a track mounted to the window sash, similar to the single arm operator. The dual arm operator also includes a second arm which has a pivot joint and which is secured at its remote end by a pivotable but fixed connection to the sash, similar to the split arm operator. Dual arm operators come in a variety of sizes to handle a variety of sash sizes.
Dual arm operators and split arm operators require different housing designs due to the different spacings between the rotational axes for the arms that rotate about a fixed axis and the worm gear. Specifically, both the dual arm operator and the split arm operator have a gear sector which rotates about a fixed axis. The radius of the gear sector for the split arm operator is larger than the radius of the gear sector for the dual arm operator. Accordingly, the distance between the rotational axis and the worm gear for the split arm operator is greater than the distance between the rotational axis and the worm gear for the dual arm operator. Hence, the base portion of the housing for the split arm operator must be configured differently than the base portion for the dual arm operator. However, this is inconvenient and costly given the fact that manufacturers often choose to utilize a single style design for both dual arm operators and single arm operators. It would be more cost efficient to generate an escutcheon/base combination which could be utilized for both split arm and dual arm operators.
Further, with both split arm and dual arm operators, the worm gear is equipped with a splined shaft that protrudes outward through the escutcheon. The splined shaft is mateably received in a shaped opening in the crank. If the crank or handle is removed, the unsightly splined shaft is left exposed. Even if a protective cap is provided for the splined shaft, the cap and shaft still protrude outwardly from the escutcheon and do not provide the sleek, low profile appearance that many interior designers and consumers demand. Therefore, there is a need for an improved worm gear assembly which provides an escutcheon having a low profile and which permits removal of the crank or handle without leaving an unsightly shaft protruding outward from the escutcheon.
Further, vinyl windows are manufactured by a number of different companies, with a number of different profiles. Accordingly, it is difficult to provide a single operator with a base that is capable of fitting the large number of vinyl window profiles that are present in the marketplace. Accordingly, there is a need for an improved base design which can be adapted to a wide variety of window profiles. Such a design would enable a single operator to be used on most or all of the vinyl windows currently being manufactured.
The present invention satisfies the aforenoted needs by providing an improved casement window operator that includes a base and an escutcheon that forms a housing for accommodating a drive gear. The base includes an elongated recess. The operator also includes a bushing. The bushing comprises an elongated flange that has a first end and a second end. The flange is connected to a shaft that extends upward from the flange. The shaft is connected to the flange at an eccentric position that is closer to the first end of the flange than the second end of the flange. The flange of the bushing is mateably accommodated in the recess of the base. The drive gear is mounted onto the shaft. The bushing may be removed from the shaft, rotated and reinserted into the recess to relocate the shaft and the drive gear with respect to the base.
By rotating the bushing, 180xc2x0, the rotational axis of the drive gear represented by the shaft of the bushing is relocated within the housing. As a result, the distance between the rotational axis of the drive gear from the worm gear is either shortened or lengthened. For a dual arm operator, the bushing is rotated so that the shaft is closer to the worm gear; for a split arm operator, the bushing is rotated so the shaft is farther away from the worm gear.
In an embodiment, the flange further comprises a raised surface that surrounds the shaft. The raised surface acts as a bearing support for the drive gear.
In an embodiment, the shaft comprises an axial hole extending through the shaft. The axial hole accommodates a screw. Further, the recess of the base also comprises two holes. A first hole accommodates the screw and is in alignment with the axial hole of the shaft when the flange of the bushing is mateably accommodated in the elongated recess in a first position. The second hole accommodates the screw and is in alignment with the axial hole of the shaft when the flange of the bushing has been rotated and is mateably accommodated in the recess in a second position.
In an embodiment, the flange comprises an underside. The underside of the flange comprises a protrusion that is spaced apart from the axial hole of the shaft. The protrusion is mateably accommodated in the second hole of the base when the bushing is in the first position. The protrusion is also mateably accommodated in the first hole of the base when the bushing is in the second position.
In an embodiment, the escutcheon comprises an underside and the shaft comprises a top end disposed opposite the shaft from the flange. The top end of the shaft engages the underside of the escutcheon.
In an embodiment, the underside of the escutcheon comprises a first recess and a second recess. The first recess receives the top end of the shaft when the bushing is in the first position; the second recess receives the top end of the shaft when the bushing is in the second position.
In an embodiment, the top end of the shaft is tapered.
In an embodiment, the first end of the flange of the bushing comprises a notch and the second end of the flange of the bushing comprises a notch. The first end of the elongated recess comprises a projection for mateably engaging the notch of the first end of the flange or the notch of the second end of the flange. Further, the second end of the elongated recess also comprises a projection for mateably engaging the notch of the first end of the flange or the notch of the second end of the flange.
In an embodiment, the base comprises an underside which comprises a lower portion disposed in registry with the escutcheon and a stepped upper portion that extends rearward from the lower portion. The window operator further comprises a spacer that engages the stepped upper portion of the underside of the base.
In an embodiment, the spacer is detachably and slidably connected to the stepped upper portion of the underside of the base.
In an embodiment, the present invention provides an improved worm drive assembly that is housed entirely within the housing defined by the base and the escutcheon as follows. Specifically, the base comprises an angled recess and an angled support. The worm drive assembly comprises a worm gear, a lower thrust bushing, a drive coupling and a retainer bushing. The worm gear comprises two ends, each end of the worm gear comprising a shaft. The shaft of one end of the worm gear is mateably received in the lower thrust bushing which, in turn, is received in the angled recess of the base. The shaft of the other end of the worm gear is mateably received in the drive coupling which, in turn, is mateably received in the retainer bushing. The retainer bushing engages the angled support of the base. The worm drive assembly is disposed entirely between the escutcheon and the base.
In an embodiment, the escutcheon comprises an underside and the retainer bushing comprises a top end that engages the underside of the escutcheon.
In an embodiment, the angled support of the base and the recess of the base support the worm drive assembly at an angle with respect to the base.
In an embodiment, the casement window operator further comprises a handle. The handle comprises an end. The escutcheon further comprises a hole for receiving the handle. The hole is in registry with the worm drive assembly. The end of the handle is mateably received in the top end of the retainer bushing.
In an embodiment, the end of the handle comprises a sidewall with a circumscribed recess. The top end of the retainer bushing comprises a radially inwardly protruding bead. The bead is received in the circumscribed recess of the end of the handle when the end of the handle is mateably received in the top end of the retainer bushing.
Other advantages and objects of the present invention will become apparent upon reading the following detailed description and appended claims, and upon reference to the accompanying drawings.